Forget about contact lenses that change the color of your eyes. The smart lenses of tomorrow may be able to do a whole lot more, courtesy of nano-scaled dialectic resonators developed by Australian researchers. The team embedded resonators in an elastomeric matrix used for contact lenses. Mechanically stretching the material changes its spectral properties. Using the technology, high-tech lenses could one day filter optical radiation without interfering with vision – or in a more advanced version, transmit data and gather live vital information or even show information like a head-up display.

Embedded in a rubberized matrix, dielectric nano resonators formed of titanium oxide alter the spectral properties of the material when it is stretched, providing a new approach to tunable filters.Contact lenses may be the jazziest application, but the spectral tunability may be far more useful in practical applications like datacom and smartphone cameras. The research combined the University of Adelaide researchers’ expertise in interaction of light and artificial materials with the materials science and nanofabrication expertise at RMIT University.

“With advanced techniques to control the properties of surfaces, we can dynamically control their filter properties, which allow us to potentially create devices for high data-rate optical communication or smart contact lenses,” says Withawat Withayachumnankul, from the University of Adelaide’s School of Electrical and Electronic Engineering. “The current challenge is that dielectric resonators only work for specific colours, but with our flexible surface we can adjust the operation range simply by stretching it.”

The devices were made by embedding titanium oxide nano crystals in the contact-lens material. “Both materials are proven to be bio-compatible, forming an ideal platform for wearable optical devices,” says Associate Professor Madhu Bhaskaran, co-Leader of the Functional Materials and Microsystems Research Group at RMIT. “By engineering the shape of these common materials, we can create a device that changes properties when stretched. This modifies the way the light interacts with and travels through the device, which holds promise of making smart contact lenses and stretchable color-changing surfaces.”

Lead author and RMIT researcher Dr. Philipp Gutruf says that the scientific hurdle overcome by the team was combining high-temperature processed titanium dioxide with the rubber-like material, and achieving nanoscale features. “With this technology, we now have the ability to develop light weight wearable optical components which also allow for the creation of futuristic devices such as smart contact lenses or flexible ultrathin smartphone cameras,” Gutruf says.